The present invention generally relates to improvements in the cushion construction for a seat.
Generally, it is proposed as the conventional seat cushion construction that a mesh frame 3 be disposed within a central opening 2 of the cushion frame 1 as shown in FIG. 19, the mesh frame 3 be stretched, supported with many tension springs 4 engaged with the cushion frame 1, and also a cushion pad 5 be placed on the mesh frame 3 and the cushion frame 1 as shown in FIG. 20, with the surface of the cushion pad 5 being covered with a trim 6a.
When a slide screw 6 for seat sliding, a slide nut 7, and so on are provided under the seat frame 1, the tension springs 4 and so on may come into contact against them, so that the mesh frame 3 cannot be lowered downwardly. Accordingly, the thickness t' of the cushion pad 5 is made thin, thus causing the cushioning property to be poor.
Also, there is another problem in that when no one is seated on the cushion, only a force sufficient to support the mesh frame 3 works on the tension springs 4. As the elastic force starts to increase due to the load of the sitter, the initial deflection of the cushion is good. But the deflection amount decreases as the load becomes larger. A so-called bottom-touching feeling is produced which causes a bad feeling to the person sitting on the cushion.